A researcher displays juvenile freshwater fat mucket mussels that will be used as stand-ins for rarer species in studies on water temperature tolerance. Study data will help researchers assess how vulnerable rare Oklahoma aquatic species will be to potential warming tied to climate change. Photo: David Martinez, USFWS. Download.

Several rare and distinctively-named creatures depend for survival on the cool, mountain-fed Little and Kiamichi River Basins in southeastern Oklahoma and southwestern Arkansas. At Little River National Wildlife Refuge and surrounding areas, the Ouachita rock pocketbook — a freshwater mussel — filters the water alongside two other endangered mussels, the scaleshell and winged mapleleaf. A small federally threatened fish called the leopard darter also hides in these upland streams.

Because streams in these river basins originate in the Ouachita Mountains, their water is relatively cool compared to streams in other ecosystems such as the Great Plains. High temperatures range from about 64 degrees Fahrenheit in winter to 84 degrees in summer — a range that suits popular game fish such as smallmouth bass.

But threats abound. Water pollution, agriculture runoff and the construction of dams and reservoirs have already shrunken habitat for these rare aquatic species. A historic drought is compounding the problem. And now, biologists speculate the fish and mussels could face another potential stressor: rising stream temperatures resulting from climate change, if projections by an intergovernmental panel prove accurate. 

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Triggered by a “perfect storm” of extended droughts, warm winters, and old, dense forests, mountain pine beetle populations have exploded across a landscape of lodgepole pine trees throughout Colorado and southeastern Wyoming. Photo: USDA Forest Service. Download.

Lodgepole pine forests in parts of Wyoming and other areas of the Intermountain West are being infested by the native mountain pine beetle – a voracious bug smaller than your little fingernail that is thriving in a warming climate.

Triggered by a “perfect storm” of extended droughts, warm winters, and old, dense forests, mountain pine beetle populations have exploded across a landscape of lodgepole pine trees throughout Colorado and southeastern Wyoming.

The mountain pine beetle is a true predator on many western pine trees because to successfully reproduce, the beetles must kill host trees. They typically kill trees already weakened by disease or old age, but even a healthy tree’s defensive mechanisms can be exhausted when beetle numbers are at epidemic levels. The beetle attacks pines in late summer, dispersing a chemical signal that attracts other beetles to mass-attack the tree. When the beetles bore through the bark of the tree, they introduce blue-stain fungus, which can work quickly to kill the tree. Trees stressed by drought and old-age are unable to produce sufficient defenses to fend off beetle attacks. The beetles form tunnels and lay eggs underneath the bark, which hatch into larvae. The larvae spend the winter underneath the bark and emerge as adults in the summer, beginning the cycle again.

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